The gastric mucosal layer which protects the stomach can be easily damaged by various factors. Typical factors of such include gastric acid, alcohols, non-steroidal anti-inflammatory drugs (NSAID) such as aspirin, bacteria such as Helicobacter pylori [Suzuki. M. and S. Miura, Nippon Rinsho, 15(12), 3154-3158, 1993], disturbance of microcirculation of gastric mucosa and hypotension caused by stress [Tadaoki Mizuno, Yokohama Med. Bull., 38(3,4), 87-97, 1987], etc. When the mucosal layer is damaged by the above factors, there occurs inflammation which is accompanied by flare, hemorrhage and edema. In severe cases, this may lead to damage in the submucosa and the muscle layer, called gastric ulcer. Further, the duodenum which is in direct contact with the stomach may get inflammation or ulcer because of the exposure to similar factors.
For the treatment of the inflammation and ulcer of the stomach and the duodenum caused by these factors, it is essential to develop a drug effective in inhibiting the secretion of gastric acid, inhibiting the proliferation of Helicobacter pylori, stimulating the secretion of mucus, promoting the regeneration of epithelial cells, fighting against inflammation, etc. At present, the most typical treatments for gastritis and gastric ulcer are H2 antagonists and proton pump inhibitors effective in inhibiting the secretion of gastric acid. These drugs are shown to have superior clinical effect [J. Int. Med. Res. 17(suppl.) 9A, 1989; Meth. Find. Exp. Clin. Pharmacol. 11(suppl. 1) 87, 1989; N. Eng. J. Med. 323: 1672, 1990]. However, these gastric acid secretion inhibitors have a drawback that the condition recurs when the administration of the drugs is stopped [Drug Intell. Clin. Pharm. 21: 493, 1987, Gut 30: 449, 1989 Yale J. Biol. Med. 65: 649, 1992].
The mucosal protectant, which promotes the regeneration of the mucosal tissue to ensure protection against the re-attack of gastritis inducing factors to reduce the recurrence of gastritis, is an important component of the gastritis treatment. Currently, such drugs as rebamipide, sofalcone, etc., are available as a gastric mucosal protectant. However, they should be taken in large amount for a long period of time due to the rather slow actions of these drugs, and thus there is a need for the development of improved drugs.
One of the most commonly used methods of assessing the efficiency of gastritis treatment using an animal model is to introduce damage on the gastric mucosa by using non-steroidal anti-inflammatory drugs (NSAID) or ethanol, and observe the rate of recovery. Through these animal model tests, various herbal extracts have been reported as candidates for the treatment of gastritis. In particular, the extract of Artemisia Spps having superior effect in treating gastritis has been applied for a patent [Korean Patent Application No. 10-1995-0021957] and developed as a commercial drug named Stillen® by Dong-A Pharmaceutical.
The Momordicae semen used in the present invention is a ripe seed of Momordica, a perennial vine which grows widely in southern China and Vietnam. Fruits harvested between September and November are cut in half and the seeds are collected when they are half dry. Or, the fruits are put into jars and the seeds are taken when the rinds become rotten. Momordicae semen is known to have good anti-inflammatory activity and be effective against rheumatic pain, muscular spasm, etc. At present, the Momordicae semen extract is known to contain sterol, oleanolic acid, momordic acid, etc.
The present inventors have made extensive efforts to develop a treatment for gastritis. In doing so, they discovered that the Momordicae semen extract and momordica saponin I isolated therefrom reduce the damage of the gastric mucosa induced by diclofenac and alcohols in rats. They also discovered that the administration of Momordicae semen extract and momordica saponin reduces the acidity in the stomach.
Accordingly, an object of the present invention is to provide a drug for the prevention and treatment of gastritis or gastric ulcer comprising Momordicae semen extract or momordica saponin I as an active ingredient which is superior in protecting the gastric mucosa and inhibiting gastric acid.